One of the masterminds of "Saturday Night Live's" digital shorts will be staying "Up All Night" this fall.Jorma Taccone, one-third of the Lonely Island comedy team (along with Andy Samberg and Akiva Schaffer) that produces the digital shorts, will guest-star in an upcoming episode of NBC's new comedy, creator Emily Spivey tells Zap2it. He'll be playing an old boyfriend of Maya Rudolph's character."You're going to see flashbacks of them from the '90s," Spivey tells us. "They have a little song together and everything, and a music video.""Up All Night" centers on new parents Reagan (Christina Applegate) and Chris (Will Arnett), who are trying to raise their baby while still keeping the trappings of their old life. Rudolph plays Ava, the host of a talk show Reagan produces.Taccone is the second "Saturday Night Live" veteran Spivey (herself an ex-"SNL" writer) has recruited to guest-star on "Up All Night." Will Forte will also appear as a guy...